Brett and Naghemeh King have been told they could be behind bars until Thursday after the judge in Madrid this afternon said it could take another 72 hours before all the papers are gathered.

A picture posted on Facebook showed Ashya with his mother Naghemeh King

The judge has asked for more documentation about Ashya's medical care, and for translations of documents handed to the court by Mr and Mrs King.

Ashya, aged five, remains under police guard in a hospital in Malaga, where he is being treated for a brain tumour after his parents took him out of a hospital in Southampton without his doctors' consent and caught a ferry to the continent.

Undated video grab taken from a video posted on YouTube by Naveed King showing him holding up a food package saying that his brother Ashya had enough food after he was taken by his parents from hospital without doctors' consent

It emerged today that Portsmouth City Council made Ashya a ward of court on Friday, the day after he left the hospital, after telling a High Court judge he was in "serious danger".

Undated handout photos issued by Hampshire Police of Brett King and Naghemeh King, the parents of Ashya King, who have legal proceedings against them continuing in Spain after they took the five-year-old brain cancer patient out of hospital without doctors' consent

His entire family, including his six siblings, are banned from visiting him in hospital in Spain.

Hampshire Police are seeking the Kings' extradition on suspicion of neglecting their son, but the Kings have insisted they took Ashya to Spain because they want him to have proton beam therapy, a treatment denied them by University Hospital Southampton.

They have won backing from Downing Street, after David Cameron made it clear he believes they are only trying to "do the very best for their child".

Mr Cameron's own son Ivan, who suffered from cerebral palsy and epilepsy, died at the age of six in 2009.

The Prime Minister's Official Spokesman said: "I think people up and down the country will understand and be moved by the grave illness from which Ashya is suffering. The priority must be that he receives the most appropriate care.

"Parental instincts are to do the very best for your child. The priority here is the little boy's health. It is also understandable that the relevent authorities take an interest in cases."

The Kings say they went to Spain to sign documents as part of the sale of a property they own there so they could afford the £90,000 it will cost for Ashya to have the proton beam therapy.

They took matters into their own hands after doctors told them their son had just four months to live.

"There is police standing outside his hospital room. We are not allowed to go and see him. We have tried to call the hospital but they are not revealing any information at all to us.

"Including taking care of all the kids, we're having to do the research ourselves to find out information. We're not getting anyone knocking on our door to tell us everything is OK. We've got lots of support from friends and family out here.

"My mum was by his (Ashya's) side for the whole month that he was in hospital so for him to now suddenly not be with anyone of the family - and because he can't really move much of his body we kept him entertained, we played games with him, we make sure that he was always happy ... his health might actually deteriorate because he can't be entertained and be happy

"We wanted the best for Ashya and for us to know that now they've taken him away from us and maybe given him treatment that may not be best for him, it's quite heartbreaking.

"Especially now that my other brothers can't see my parents, that's heartbreaking for them."

Mr King's mother Patricia King said the way they had been treated was an "absolute disgrace".

She said: "They (the authorities) are the ones who are cruel because they have taken poor little Ashya who is dying of a brain tumour and they won't let the parents, my son and daughter-in-law, they won't let them see him at all.

"It's terrible, it is so cruel it is unbelieveable.

"To try and make out that he has been neglected well. Why haven't we got any human rights? They keep on, the EU, about human rights. Where are our human rights? We have got none."

The family had hoped to take Ashya to Prague for proton therapy once they had made arrangements in Spain to sell their property there.

The Prague Proton Therapy Centre confirmed today that Mr King first contacted its staff on August 20.

Dr Jiri Kubes, head of proton therapy, said: "The center is ready to accept Ashya King immediately if the specialists receive proper medical documentation from the UK doctors."

However, doctors in Southampton are understood to have advised Mr and Mrs King that Ashya would not be a suitable candidate for proton therapy.